DETAILED ACTION
1. Claims 1-33 of U.S. Application 18/905329 filed on October 3, 2024 are presented for examination.
Notice of Pre-AIA or AIA Status
2. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Information Disclosure Statement
3. The information disclosure statements (IDS) submitted on January 16, 2025, June 12, 2025 and April 27, 2026 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements are being considered by the examiner.
Claim Rejections - 35 USC § 102
4. The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
5. Claims 1, 3-7, 11, 25, 26, 29 and 30 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Cho (KR 20220149978, see English Machine Translation attached).
Regarding claim 1, Cho teaches (see figs. 2-5 below) an axial flux electric machine (title, Abstract) comprising: a stator (130) (page 3);
a rotor (120) spaced apart from the stator (130) in an axial direction of the axial flux electric machine to form an air gap (see annotated fig. 2 below) (page 3); and
at least one impeller (140) on the rotor; wherein the at least one impeller (140) includes a rotor gap (see annotated fig. 5 below) through the rotor (120) and an airfoil element (see annotated fig. 5 below) (pages 3-4).
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Regarding claim 3/1, Cho teaches (see figs. 2-5 above and fig. 6 below) the at least one impeller (140) is configured to form a pressure gradient (as shown by airfoil in annotated fig. 6 below) across a surface of the rotor (120) when the rotor rotates (pages 3-4).
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Regarding claim 4/1, Cho teaches (see figs. 2-6 above) the airfoil element is configured to form a pressure gradient across a surface of the rotor (120) when the rotor rotates; and the rotor gap (see annotated fig. 5 above) is configured to form a fluid path from the air gap to a back side of the rotor (120) (pages 3-4).
Regarding claim 5/1, Cho teaches (see figs. 2-6 above) a rotor shaft (110) attached to the rotor (120); and a fan (140) attached to the rotor shaft (110) (pages 3-4).
Regarding claim 6/1, Cho teaches (see figs. 2-6 above) the rotor gap (see annotated fig. 5 above) and the airfoil element (see annotated fig. 5 above) are formed on the rotor (120) (pages 3-4).
Regarding claim 7/1, Cho teaches (see figs. 2-6 above) a back iron (121) of the rotor (120); wherein the rotor gap (see annotated fig. 5 above) comprises a window through the back iron (121) (pages 3-4).
Regarding claim 11/1, Cho teaches (see figs. 2-6 above) the rotor gap (see annotated fig. 5 above) is etched (product by process limitation not given patentable weight, see below) into the rotor (120); and the airfoil element (see annotated fig. 5 above) is attached to the rotor (120) (pages 3-4).
The Examiner points out the limitation of “the rotor gap is etched” is considered as a product-by-process limitation. “Even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” In re Thorpe, 777F, 2d 659, 698, 227 USPQ 964, 966 (Fed. Cir. 1985); see also MPEP 2113.
Regarding claim 25, Cho teaches (see figs. 2-6 above) an axial flux electric machine (title, Abstract) comprising: a stator (130) (page 3);
a rotor (120) spaced apart from the stator (130) in an axial direction of the axial flux electric machine to form an air gap (see annotated fig. 2 above) (page 3);
a rotor shaft (110) attached to the rotor (120); and a fan (140) attached to the rotor shaft (110) and to the rotor (120) (pages 3-4).
Regarding claim 26, Cho teaches (see figs. 2-6 above) a method for cooling an axial flux electric machine (Abstract, page 2) comprising:
rotating a rotor (120) relative to a stator (130), the rotor (120) being spaced apart from the stator (130) in an axial direction of the axial flux electric machine to form an air gap (see annotated fig. 2 above) and the rotor (120) comprising a set of impellers (140) (page 3); and
forming, using the set of impellers (140) and based at least in part on rotating the rotor (120), a pressure gradient (as shown by airfoil in annotated fig. 6 above) across a surface of the rotor (120) (pages 3-4).
Regarding claim 29/26, Cho teaches (see figs. 2-6 above) each impeller of the set of impellers (140) comprises an airfoil element (see annotated fig. 5 above); and the pressure gradient is formed based at least in part on the airfoil element (see annotated fig. 5 above) of an impeller (140) (pages 3-4).
Regarding claim 30/26, Cho teaches (see figs. 2-6 above) each impeller of the set of impellers (140) comprises a rotor gap (see annotated fig. 5 above) through the rotor (120), and further comprising: forming a fluid path from the air gap to a back side of the rotor (120) based at least in part on the rotor gap (see annotated fig. 5 above) of an impeller (140) (pages 3-4).
Claim Rejections - 35 USC § 103
6. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
7. Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Cho in view of Lines (US 20220094229).
Regarding claim 2/1, Cho teaches the device of claim 1 but does not explicitly teach the axial flux electric machine is yokeless.
However, Lines teaches the axial flux electric machine is yokeless (¶ 122; ¶ 123; ¶ 190) in order to reduce weight and improve the efficiency of the device (Lines, ¶ 190).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Cho and provide the axial flux electric machine is yokeless as taught by Lines in order to reduce weight and improve the efficiency of the device (Lines, ¶ 190).
8. Claims 10 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Cho in view of Hano (US 20160329796).
Regarding claim 10/1, Cho teaches the device of claim 1 but does not explicitly teach the airfoil element comprises an airfoil on an outer edge of the rotor.
However, Hano teaches (see fig. 17b below) the airfoil element (12) comprises an airfoil on an outer edge of the rotor (3, 4) (¶ 106; ¶ 107) in order to provide improved cooling efficiency (Hano, ¶ 105; ¶ 106).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Cho and provide the airfoil element comprises an airfoil on an outer edge of the rotor as taught by Hano in order to provide improved cooling efficiency (Hano, ¶ 105; ¶ 106).
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Regarding claim 13/1, Cho teaches the device of claim 1 but does not explicitly teach a set of segmented magnets on the rotor; wherein: (i) the at least one impeller includes a set of airfoil elements; and the set of airfoil elements extend from a center of the rotor towards an outer edge of the rotor and between magnets in the set of segmented magnets.
However, Hano teaches (see fig. 17b above) a set of segmented magnets (9) on the rotor (3, 4); wherein: (i) the at least one impeller includes a set of airfoil elements (12); and the set of airfoil elements (12) extend from a center of the rotor (3, 4) towards an outer edge of the rotor (3, 4) and between magnets (9) in the set of segmented magnets (9) (¶ 66; ¶ 67; ¶ 105 to ¶ 107) in order to provide improved cooling efficiency (Hano, ¶ 105; ¶ 106).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Cho and provide a set of segmented magnets on the rotor; wherein: (i) the at least one impeller includes a set of airfoil elements; and the set of airfoil elements extend from a center of the rotor towards an outer edge of the rotor and between magnets in the set of segmented magnets as taught by Hano in order to provide improved cooling efficiency (Hano, ¶ 105; ¶ 106).
9. Claims 15, 17-23, 27 and 32 are rejected under 35 U.S.C. 103 as being unpatentable over Cho in view of Gabrys (US 7750515).
Regarding claim 15/1, Cho teaches the device of claim 1 but does not explicitly teach the airfoil element extends from the rotor in a direction that is away from the stator.
However, Gabrys teaches (see fig. 5 below) the airfoil element (120, 121) extends from the rotor (103, 104) in a direction that is away from the stator (102) (fig. 5; col. 7: 20-25, 50-67) in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Cho and provide the airfoil element extends from the rotor in a direction that is away from the stator as taught by Gabrys in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
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Regarding claim 17/1, Cho teaches the device of claim 1 but does not explicitly teach a motor housing; wherein airflow created by the at least one impeller transfers heat from the air gap to the motor housing.
However, Gabrys teaches (see fig. 5 above) a motor housing (112); wherein airflow created by the at least one impeller (120, 121) transfers heat from the air gap to the motor housing (112) (Abstract; col. 7: 20-25, 50-67) in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Cho and provide a motor housing; wherein airflow created by the at least one impeller transfers heat from the air gap to the motor housing as taught by Gabrys in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Regarding claim 18/17/1, Cho in view of Gabrys teaches the device of claim 17 but does not explicitly teach the motor housing includes a set of pins or a set of fins; and the airflow created by the at least one impeller transfers heat from the air gap to the motor housing via thermal contact between the air gap and the set of fins or the set of pins.
However, Gabrys further teaches (see fig. 5 above) the motor housing (112) includes a set of pins (124, 125) or a set of fins (124, 125); and the airflow created by the at least one impeller (120, 121) transfers heat from the air gap to the motor housing (112) via thermal contact between the air gap and the set of fins (124, 125) or the set of pins (124, 125) (Abstract; col. 7: 20-25, 50-67) in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Cho in view of Gabrys and provide the motor housing includes a set of pins or a set of fins; and the airflow created by the at least one impeller transfers heat from the air gap to the motor housing via thermal contact between the air gap and the set of fins or the set of pins as further taught by Gabrys in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Regarding claim 19/17/1, Cho in view of Gabrys teaches the device of claim 17 but does not explicitly teach a set of pins or a set of fins attached to the motor housing, wherein the airflow created by the at least one impeller transfers heat from the air gap to the motor housing via the set of fins or the set of pins.
However, Gabrys further teaches (see fig. 5 above) a set of pins (124, 125) or a set of fins (124, 125) attached to the motor housing (112), wherein the airflow created by the at least one impeller (120, 121) transfers heat from the air gap to the motor housing (112) via the set of fins (124, 125) or the set of pins (124, 125) (Abstract; col. 7: 20-25, 50-67) in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Cho in view of Gabrys and provide a set of pins or a set of fins attached to the motor housing, wherein the airflow created by the at least one impeller transfers heat from the air gap to the motor housing via the set of fins or the set of pins as further taught by Gabrys in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Regarding claim 20/17/1, Cho in view of Gabrys teaches the device of claim 17 but does not explicitly teach a set of thermal features on the motor housing that are configured to increase turbulence and a surface area of the motor housing.
However, Gabrys further teaches (see fig. 5 above) a set of thermal features (124, 125) on the motor housing (112) that are configured to increase turbulence and a surface area of the motor housing (112) (Abstract; col. 7: 20-25, 50-67) in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Cho in view of Gabrys and provide a set of thermal features on the motor housing that are configured to increase turbulence and a surface area of the motor housing as further taught by Gabrys in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Regarding claim 21/20/17/1, Cho in view of Gabrys teaches the device of claim 20 but does not explicitly teach the set of thermal features are one of straight fins, curved fins, straight pins, and curved pins.
However, Gabrys further teaches (see fig. 5 above) the set of thermal features (124, 125) are one of straight fins, curved fins, straight pins, and curved pins (fig. 5; Abstract; col. 7: 20-25, 50-67) in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Cho in view of Gabrys and provide the set of thermal features are one of straight fins, curved fins, straight pins, and curved pins as further taught by Gabrys in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Regarding claim 22/17/1, Cho in view of Gabrys teaches the device of claim 17, but does not explicitly teach a set of airfoil guide elements on the motor housing; wherein the set of airfoil guide elements are configured to guide air towards the air gap.
However, Gabrys further teaches (see fig. 5 above) a set of airfoil guide elements (120, 121) on the motor housing (112); wherein the set of airfoil guide elements (120, 121) are configured to guide air towards the air gap (fig. 5; Abstract; col. 7: 20-25, 50-67) in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Cho in view of Gabrys and provide a set of airfoil guide elements on the motor housing; wherein the set of airfoil guide elements are configured to guide air towards the air gap as further taught by Gabrys in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Regarding claim 23/1, Cho teaches the device of claim 1 but does not explicitly teach a second rotor spaced apart from the stator in the axial direction to form a second air gap, wherein the air gap and the second air gap are on opposite sides of the stator; wherein the airfoil element is configured to form a pressure gradient across a surface of the second rotor when the second rotor rotates.
However, Gabrys further teaches (see fig. 5 above) a second rotor (104) spaced apart from the stator (102) in the axial direction to form a second air gap, wherein the air gap and the second air gap are on opposite sides of the stator (102); wherein the airfoil element (121) is configured to form a pressure gradient across a surface of the second rotor (104) when the second rotor (104) rotates (fig. 5; col. 7: 20-25, 50-67) in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Cho and provide a second rotor spaced apart from the stator in the axial direction to form a second air gap, wherein the air gap and the second air gap are on opposite sides of the stator; wherein the airfoil element is configured to form a pressure gradient across a surface of the second rotor when the second rotor rotates as taught by Gabrys in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Regarding claim 27/26, Cho teaches the method of claim 26 but does not explicitly teach rotating the rotor comprises rotating the rotor at a first speed and further comprising: rotating the rotor relative to the stator at a second speed, the second speed being different than the first speed.
However, Gabrys teaches (see fig. 5 above and fig. 3 below) rotating the rotor (103, 104) comprises rotating the rotor at a first speed and further comprising: rotating the rotor (103, 104) relative to the stator (102) at a second speed, the second speed being different than the first speed (fig. 3 is a graph of the rotor operation at different speeds) (col. 6: 42-67; col. 7: 1-17) in order to provide optimal efficiency while operating at various load and speed settings (Gabry’s, col. 6: 42-67; col. 7: 1-17).
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Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Cho and provide rotating the rotor comprises rotating the rotor at a first speed and further comprising: rotating the rotor relative to the stator at a second speed, the second speed being different than the first speed as taught by Gabrys in order to provide optimal efficiency while operating at various load and speed settings (Gabry’s, col. 6: 42-67; col. 7: 1-17).
Regarding claim 32/26, Cho teaches the method of claim 26 but does not explicitly teach rotating a second rotor relative to the stator, the second rotor being spaced apart from the stator in the axial direction of the axial flux electric machine to form a second air gap and the second rotor comprising a second set of impellers; and forming, using the second set of impellers and based at least in part on rotating the second rotor, a second pressure gradient across a surface of the second rotor.
However, Gabrys further teaches (see fig. 5 above) rotating a second rotor (104) relative to the stator (102), the second rotor (104) being spaced apart from the stator (102) in the axial direction of the axial flux electric machine to form a second air gap and the second rotor (104) comprising a second set of impellers (121); and forming, using the second set of impellers (121) and based at least in part on rotating the second rotor (104), a second pressure gradient across a surface of the second rotor (104) (fig. 5; col. 7: 20-25, 50-67) in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Cho and provide rotating a second rotor relative to the stator, the second rotor being spaced apart from the stator in the axial direction of the axial flux electric machine to form a second air gap and the second rotor comprising a second set of impellers; and forming, using the second set of impellers and based at least in part on rotating the second rotor, a second pressure gradient across a surface of the second rotor as taught by Gabrys in order to reduce operating temperature of the device and improve cooling efficiency (Gabrys, col. 7: 55-67; col. 8: 1-5).
Allowable Subject Matter
10. Claims 8, 9, 12, 14, 16, 24, 28, 31 and 33 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Conclusion
11. Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALEXANDER A SINGH whose telephone number is (571)270-0243. The examiner can normally be reached M-F 9am to 5pm.
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/ALEXANDER A SINGH/Primary Examiner, Art Unit 2834
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